Global warming leads to more and more natural disasters, a major earthquake in Sichuan had injured more than three hundred thousand people, many victims had become disabled persons thereafter. Coupled with the aging population, there is increasing number of wheelchair users. Wheelchair is very difficult to maneuver, especially to those beginners and elderly persons living in hilly regions. When a wheelchair is driven and propelled by a user or someone else for going up or down a hill or ramp, if the wheelchair driver is exhausted in midway, the wheelchair will rapidly slide forwardly or backwardly in a few seconds and cause a danger. To solve the problem on ramp travel, it is important that the wheelchair speed could be reduced while going down the ramp, and the driver could take a rest on occasion while going up the ramp, and no physical strength is needed to keep the wheelchair from rolling backwards.
As there is increasing number of wheelchair users in recent years, there are many new products launched in the market, such as anti-rollback wheels, bicycle-style hand brakes, oxygen bottle racks, and the like. An anti-rollback wheel merely serves as a safety wheel to prevent the user from falling out of the wheelchair when the wheelchair is inclined backwardly. A bicycle-style hand brake may be used for reducing the speed of the wheelchair while going down the ramp, but the wheelchair might be out of control if the user had gripped the hand brake for too long and became exhausted.